diff --git a/openflow/ctl/src/main/java/org/onlab/onos/of/controller/impl/RoleManager.java b/openflow/ctl/src/main/java/org/onlab/onos/of/controller/impl/RoleManager.java
new file mode 100644
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+++ b/openflow/ctl/src/main/java/org/onlab/onos/of/controller/impl/RoleManager.java
@@ -0,0 +1,395 @@
+package org.onlab.onos.of.controller.impl;
+
+import java.io.IOException;
+import java.util.Collections;
+
+import org.onlab.onos.of.controller.RoleState;
+import org.onlab.onos.of.controller.driver.OpenFlowSwitchDriver;
+import org.onlab.onos.of.controller.driver.RoleHandler;
+import org.onlab.onos.of.controller.driver.RoleRecvStatus;
+import org.onlab.onos.of.controller.driver.RoleReplyInfo;
+import org.onlab.onos.of.controller.driver.SwitchStateException;
+import org.projectfloodlight.openflow.protocol.OFControllerRole;
+import org.projectfloodlight.openflow.protocol.OFErrorMsg;
+import org.projectfloodlight.openflow.protocol.OFErrorType;
+import org.projectfloodlight.openflow.protocol.OFExperimenter;
+import org.projectfloodlight.openflow.protocol.OFFactories;
+import org.projectfloodlight.openflow.protocol.OFMessage;
+import org.projectfloodlight.openflow.protocol.OFNiciraControllerRole;
+import org.projectfloodlight.openflow.protocol.OFNiciraControllerRoleReply;
+import org.projectfloodlight.openflow.protocol.OFRoleReply;
+import org.projectfloodlight.openflow.protocol.OFRoleRequest;
+import org.projectfloodlight.openflow.protocol.OFVersion;
+import org.projectfloodlight.openflow.protocol.errormsg.OFBadRequestErrorMsg;
+import org.projectfloodlight.openflow.protocol.errormsg.OFRoleRequestFailedErrorMsg;
+import org.projectfloodlight.openflow.types.U64;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * A utility class to handle role requests and replies for this channel.
+ * After a role request is submitted the role changer keeps track of the
+ * pending request, collects the reply (if any) and times out the request
+ * if necessary.
+ *
+ * To simplify role handling we only keep track of the /last/ pending
+ * role reply send to the switch. If multiple requests are pending and
+ * we receive replies for earlier requests we ignore them. However, this
+ * way of handling pending requests implies that we could wait forever if
+ * a new request is submitted before the timeout triggers. If necessary
+ * we could work around that though.
+ */
+class RoleManager implements RoleHandler {
+    protected static final long NICIRA_EXPERIMENTER = 0x2320;
+
+    private static Logger log = LoggerFactory.getLogger(RoleManager.class);
+    // indicates that a request is currently pending
+    // needs to be volatile to allow correct double-check idiom
+    private volatile boolean requestPending;
+    // the transaction Id of the pending request
+    private int pendingXid;
+    // the role that's pending
+    private RoleState pendingRole;
+
+    // the expectation set by the caller for the returned role
+    private RoleRecvStatus expectation;
+    private final OpenFlowSwitchDriver sw;
+
+
+    public RoleManager(OpenFlowSwitchDriver sw) {
+        this.requestPending = false;
+        this.pendingXid = -1;
+        this.pendingRole = null;
+        this.expectation = RoleRecvStatus.MATCHED_CURRENT_ROLE;
+        this.sw = sw;
+    }
+
+    /**
+     * Send NX role request message to the switch requesting the specified
+     * role.
+     *
+     * @param role role to request
+     */
+    private int sendNxRoleRequest(RoleState role) throws IOException {
+        // Convert the role enum to the appropriate role to send
+        OFNiciraControllerRole roleToSend = OFNiciraControllerRole.ROLE_OTHER;
+        switch (role) {
+        case MASTER:
+            roleToSend = OFNiciraControllerRole.ROLE_MASTER;
+            break;
+        case SLAVE:
+        case EQUAL:
+        default:
+            // ensuring that the only two roles sent to 1.0 switches with
+            // Nicira role support, are MASTER and SLAVE
+            roleToSend = OFNiciraControllerRole.ROLE_OTHER;
+            log.warn("Sending Nx Role.SLAVE to switch {}.", sw);
+        }
+        int xid = sw.getNextTransactionId();
+        OFExperimenter roleRequest = OFFactories.getFactory(OFVersion.OF_10)
+                .buildNiciraControllerRoleRequest()
+                .setXid(xid)
+                .setRole(roleToSend)
+                .build();
+        sw.write(Collections.<OFMessage>singletonList(roleRequest));
+        return xid;
+    }
+
+    private int sendOF13RoleRequest(RoleState role) throws IOException {
+        // Convert the role enum to the appropriate role to send
+        OFControllerRole roleToSend = OFControllerRole.ROLE_NOCHANGE;
+        switch (role) {
+        case EQUAL:
+            roleToSend = OFControllerRole.ROLE_EQUAL;
+            break;
+        case MASTER:
+            roleToSend = OFControllerRole.ROLE_MASTER;
+            break;
+        case SLAVE:
+            roleToSend = OFControllerRole.ROLE_SLAVE;
+            break;
+        default:
+            log.warn("Sending default role.noChange to switch {}."
+                    + " Should only be used for queries.", sw);
+        }
+
+        int xid = sw.getNextTransactionId();
+        OFRoleRequest rrm = OFFactories.getFactory(OFVersion.OF_13)
+                .buildRoleRequest()
+                .setRole(roleToSend)
+                .setXid(xid)
+                //FIXME fix below when we actually use generation ids
+                .setGenerationId(U64.ZERO)
+                .build();
+        sw.sendMsg(rrm);
+        return xid;
+    }
+
+    @Override
+    public synchronized boolean sendRoleRequest(RoleState role, RoleRecvStatus exp)
+            throws IOException {
+        this.expectation = exp;
+
+        if (sw.factory().getVersion() == OFVersion.OF_10) {
+            Boolean supportsNxRole = sw.supportNxRole();
+            if (!supportsNxRole) {
+                log.debug("Switch driver indicates no support for Nicira "
+                        + "role request messages. Not sending ...");
+                handleUnsentRoleMessage(role,
+                        expectation);
+                return false;
+            }
+            // OF1.0 switch with support for NX_ROLE_REQUEST vendor extn.
+            // make Role.EQUAL become Role.SLAVE
+            role = (role == RoleState.EQUAL) ? RoleState.SLAVE : role;
+            pendingXid = sendNxRoleRequest(role);
+            pendingRole = role;
+            requestPending = true;
+        } else {
+            // OF1.3 switch, use OFPT_ROLE_REQUEST message
+            pendingXid = sendOF13RoleRequest(role);
+            pendingRole = role;
+            requestPending = true;
+        }
+        return true;
+    }
+
+    private void handleUnsentRoleMessage(RoleState role,
+            RoleRecvStatus exp) throws IOException {
+        // typically this is triggered for a switch where role messages
+        // are not supported - we confirm that the role being set is
+        // master
+        if (exp != RoleRecvStatus.MATCHED_SET_ROLE) {
+
+            log.error("Expected MASTER role from registry for switch "
+                    + "which has no support for role-messages."
+                    + "Received {}. It is possible that this switch "
+                    + "is connected to other controllers, in which "
+                    + "case it should support role messages - not "
+                    + "moving forward.", role);
+
+        }
+
+    }
+
+
+    @Override
+    public synchronized RoleRecvStatus deliverRoleReply(RoleReplyInfo rri)
+            throws SwitchStateException {
+        if (!requestPending) {
+            RoleState currentRole = (sw != null) ? sw.getRole() : null;
+            if (currentRole != null) {
+                if (currentRole == rri.getRole()) {
+                    // Don't disconnect if the role reply we received is
+                    // for the same role we are already in.
+                    log.debug("Received unexpected RoleReply from "
+                            + "Switch: {}. "
+                            + "Role in reply is same as current role of this "
+                            + "controller for this sw. Ignoring ...",
+                            sw.getStringId());
+                    return RoleRecvStatus.OTHER_EXPECTATION;
+                } else {
+                    String msg = String.format("Switch: [%s], "
+                            + "received unexpected RoleReply[%s]. "
+                            + "No roles are pending, and this controller's "
+                            + "current role:[%s] does not match reply. "
+                            + "Disconnecting switch ... ",
+                            sw.getStringId(),
+                            rri, currentRole);
+                    throw new SwitchStateException(msg);
+                }
+            }
+            log.debug("Received unexpected RoleReply {} from "
+                    + "Switch: {}. "
+                    + "This controller has no current role for this sw. "
+                    + "Ignoring ...", new Object[] {rri,
+                            sw.getStringId(), });
+            return RoleRecvStatus.OTHER_EXPECTATION;
+        }
+
+        int xid = (int) rri.getXid();
+        RoleState role = rri.getRole();
+        // XXX S should check generation id meaningfully and other cases of expectations
+
+        if (pendingXid != xid) {
+            log.debug("Received older role reply from " +
+                    "switch {} ({}). Ignoring. " +
+                    "Waiting for {}, xid={}",
+                    new Object[] {sw.getStringId(), rri,
+                    pendingRole, pendingXid });
+            return RoleRecvStatus.OLD_REPLY;
+        }
+
+        if (pendingRole == role) {
+            log.debug("Received role reply message from {} that matched "
+                    + "expected role-reply {} with expectations {}",
+                    new Object[] {sw.getStringId(), role, expectation});
+
+            if (expectation == RoleRecvStatus.MATCHED_CURRENT_ROLE ||
+                    expectation == RoleRecvStatus.MATCHED_SET_ROLE) {
+                return expectation;
+            } else {
+                return RoleRecvStatus.OTHER_EXPECTATION;
+            }
+        }
+
+        // if xids match but role's don't, perhaps its a query (OF1.3)
+        if (expectation == RoleRecvStatus.REPLY_QUERY) {
+            return expectation;
+        }
+
+        return RoleRecvStatus.OTHER_EXPECTATION;
+    }
+
+    /**
+     * Called if we receive an  error message. If the xid matches the
+     * pending request we handle it otherwise we ignore it.
+     *
+     * Note: since we only keep the last pending request we might get
+     * error messages for earlier role requests that we won't be able
+     * to handle
+     */
+    @Override
+    public synchronized RoleRecvStatus deliverError(OFErrorMsg error)
+            throws SwitchStateException {
+        if (!requestPending) {
+            log.debug("Received an error msg from sw {}, but no pending "
+                    + "requests in role-changer; not handling ...",
+                    sw.getStringId());
+            return RoleRecvStatus.OTHER_EXPECTATION;
+        }
+        if (pendingXid != error.getXid()) {
+            if (error.getErrType() == OFErrorType.ROLE_REQUEST_FAILED) {
+                log.debug("Received an error msg from sw {} for a role request,"
+                        + " but not for pending request in role-changer; "
+                        + " ignoring error {} ...",
+                        sw.getStringId(), error);
+            }
+            return RoleRecvStatus.OTHER_EXPECTATION;
+        }
+        // it is an error related to a currently pending role request message
+        if (error.getErrType() == OFErrorType.BAD_REQUEST) {
+            log.error("Received a error msg {} from sw {} for "
+                    + "pending role request {}. Switch driver indicates "
+                    + "role-messaging is supported. Possible issues in "
+                    + "switch driver configuration?", new Object[] {
+                            ((OFBadRequestErrorMsg) error).toString(),
+                            sw.getStringId(), pendingRole
+                    });
+            return RoleRecvStatus.UNSUPPORTED;
+        }
+
+        if (error.getErrType() == OFErrorType.ROLE_REQUEST_FAILED) {
+            OFRoleRequestFailedErrorMsg rrerr =
+                    (OFRoleRequestFailedErrorMsg) error;
+            switch (rrerr.getCode()) {
+            case BAD_ROLE:
+                // switch says that current-role-req has bad role?
+                // for now we disconnect
+                // fall-thru
+            case STALE:
+                // switch says that current-role-req has stale gen-id?
+                // for now we disconnect
+                // fall-thru
+            case UNSUP:
+                // switch says that current-role-req has role that
+                // cannot be supported? for now we disconnect
+                String msgx = String.format("Switch: [%s], "
+                        + "received Error to for pending role request [%s]. "
+                        + "Error:[%s]. Disconnecting switch ... ",
+                        sw.getStringId(),
+                        pendingRole, rrerr);
+                throw new SwitchStateException(msgx);
+            default:
+                break;
+            }
+        }
+
+        // This error message was for a role request message but we dont know
+        // how to handle errors for nicira role request messages
+        return RoleRecvStatus.OTHER_EXPECTATION;
+    }
+
+    /**
+     * Extract the role from an OFVendor message.
+     *
+     * Extract the role from an OFVendor message if the message is a
+     * Nicira role reply. Otherwise return null.
+     *
+     * @param experimenterMsg message
+     * @return The role in the message if the message is a Nicira role
+     * reply, null otherwise.
+     * @throws SwitchStateException If the message is a Nicira role reply
+     * but the numeric role value is unknown.
+     */
+    @Override
+    public RoleState extractNiciraRoleReply(OFExperimenter experimenterMsg)
+            throws SwitchStateException {
+        int vendor = (int) experimenterMsg.getExperimenter();
+        if (vendor != 0x2320) {
+            return null;
+        }
+        OFNiciraControllerRoleReply nrr =
+                (OFNiciraControllerRoleReply) experimenterMsg;
+
+        RoleState role = null;
+        OFNiciraControllerRole ncr = nrr.getRole();
+        switch(ncr) {
+        case ROLE_MASTER:
+            role = RoleState.MASTER;
+            break;
+        case ROLE_OTHER:
+            role = RoleState.EQUAL;
+            break;
+        case ROLE_SLAVE:
+            role = RoleState.SLAVE;
+            break;
+        default: //handled below
+        }
+
+        if (role == null) {
+            String msg = String.format("Switch: [%s], "
+                    + "received NX_ROLE_REPLY with invalid role "
+                    + "value %s",
+                    sw.getStringId(),
+                    nrr.getRole());
+            throw new SwitchStateException(msg);
+        }
+        return role;
+    }
+
+    /**
+     * Extract the role information from an OF1.3 Role Reply Message.
+     *
+     * @param rrmsg the role message
+     * @return RoleReplyInfo object
+     * @throws SwitchStateException if the role information could not be extracted.
+     */
+    @Override
+    public RoleReplyInfo extractOFRoleReply(OFRoleReply rrmsg)
+            throws SwitchStateException {
+        OFControllerRole cr = rrmsg.getRole();
+        RoleState role = null;
+        switch(cr) {
+        case ROLE_EQUAL:
+            role = RoleState.EQUAL;
+            break;
+        case ROLE_MASTER:
+            role = RoleState.MASTER;
+            break;
+        case ROLE_SLAVE:
+            role = RoleState.SLAVE;
+            break;
+        case ROLE_NOCHANGE: // switch should send current role
+        default:
+            String msg = String.format("Unknown controller role %s "
+                    + "received from switch %s", cr, sw);
+            throw new SwitchStateException(msg);
+        }
+
+        return new RoleReplyInfo(role, rrmsg.getGenerationId(), rrmsg.getXid());
+    }
+
+}
+